because they are more compatible and the chemistry between them is just so adorable.
Also! he secretly smiles most of the time whenever Jie Er is with him.
Jie Er you can sort of tell that she has a little thing for Dong Fan Xiang.

she definitely end up with DFX cuz they secretly like each other and they just saying/expressing/doing mean thing to each other, but deep down they like each other...opening song...its show that they hug each other....and they look cute together...they have chemistry and funny to watch...:D